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  • 1.  how to migrate multiple LPARS at once with nimadm

    Posted Tue November 29, 2022 05:33 AM

    Dear community,

    AIX 7.3 is going to be the next OS in our environment. For that I started to prepare the migration process.
    And here comes my question.
    As nimadm can only migrate one by one lpar, how do you / how would you parallelize this to migrate multiple LPAR's at once.

    I tried with "nohup" and GNU parallel, but the resource management is not very satisfying... Only one or two threads are used per process.

    Thanks for your support in advance.

    Best regards.



    ------------------------------
    Joerg Kauke
    Unix Administrator
    COOP Switzerland
    ------------------------------


  • 2.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Wed November 30, 2022 04:19 AM
    Hello Joerg, 

    Currently, there are no other options or alternatives besides running multiple NIMADMs with "nohup" or similar tools which should work fine, but its not the fastest solution. 

    However we would love to see this a an request for enchantment at https://www.ibm.com/developerworks/rfe/execute?use_case=changeRequestLanding
    Please, take a few minutes to submit your request and hopefully in the future we'll get this voted up and implemented in to AIX. 





    ------------------------------
    Nayden Stoyanov
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  • 3.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Thu December 01, 2022 03:10 AM
    Edited by Joerg Kauke Thu December 01, 2022 05:09 AM

    Hi Nayden,

    and here is my posted "Idea"...

    https://ibm-power-systems.ideas.ibm.com/ideas/AIX-I-658

    You can vote if you would like to have that feature to... maybe in AIX 7.4  :-)

    Best regards,

    Joerg



    ------------------------------
    Joerg Kauke
    Unix Administrator
    COOP Switzerland
    ------------------------------



  • 4.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Wed November 30, 2022 08:49 AM
    Hi Joerg,

    So far we've successfully run a total of 5 parallel nimadm processes from a single NIM (E1080, CPU: VP=3, EC=1.5 Memory: 16GB). We use nimadm caching and have created a number of nimadmvgXX VGs each with a single 128GB LUN (same size as our rootvg(s)) so that the NIM client is cached to its own NIM hosted (cache) VG.

    We split the nimadm process into two sections, Phases 1-6 and Phases 7-12, as we need to re-expand the cached NIM client filesystems on the NIM itself so that during Phase 7 we have enough space to perform lpp and rpm install/upgrade work.

    1) nimadm -j nimadmvg1 -l 7302lpp_res -c <LPAR-name> -s 7302spot_res -a AIX73premigration -z AIX73postmigration -d hdiskX -P1,2,3,4,5,6 -Y

    2) Re-expand selected filesystems

    3) nimadm -j nimadmvg1 -l 7302lpp_res -c <LPAR-name> -s 7302spot_res -a AIX73premigration -z AIX73postmigration -d hdiskX -P7,8,9,10,11,12 -Y

    Performance wise, we use LPAR2RRD (https://lpar2rrd.com) to check throughput etc. and with the 5 running in parallel we hardly saw any spikes and certainly no contention. The overall runtime per nimadm process does vary, we've found, with some taking just over the hour to complete whilst others are closer to 1hr 40min and then we re-boot out of hours.

    Hope that helps.

    Regards, Steve

    ------------------------------
    Steve Munday
    AIX, IBM i, HMC, PowerVM
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  • 5.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Thu December 01, 2022 03:06 AM

    Hello Steve,

    we although track our systems with lpar2rrd and nmon. But our picture is a different one. In lpar2rrd the CPU workload is at 90 to 100% while migrating and I tested how many phys. CPU are needed to get the workload under 90%...

    So, we would need one allocated processor unit per lpar to migrate. In my case, I had a system with four physical cores to migrate 4 lpars simultaneously.
    But nmon shows, that only two threads per CPU were used.

    best regards,

    Joerg



    ------------------------------
    Joerg Kauke
    Unix Administrator
    COOP Switzerland
    ------------------------------